/**
 * Copyright (c) 2005, Regents of the University of California
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * Neither the name of the University of California, Los Angeles nor the
 * names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Creation date: Oct 3, 2005
 */

package jintgen.types;

import cck.parser.AbstractToken;
import cck.util.Util;
import java.util.List;

/**
 * The <code>SignDimension</code> class represents a sign dimension that applies to integer
 * variables. The sign dimension indicates the presence of a signed bit.
 *
 * @author Ben L. Titzer
 */
public class SignDimension extends TypeCon.Dimension {

    public SignDimension() {
        super("sign");
    }

    public Object build(TypeEnv te, List params) {
        boolean signed = true;
        if ( params.size() > 1) throw Util.failure("sign type dimension expects 0 or 1 parameters");
        if ( params.size() == 1 ) {
            Object obj = params.get(0);
            if ( obj instanceof AbstractToken )
                signed = isSigned(((AbstractToken)obj).image);
            else if ( obj instanceof String )
                signed = isSigned((String)obj);
            else if ( obj instanceof Boolean )
                signed = (Boolean)obj;
            else throw Util.failure("sign type dimension expects AbstractToken, String or Boolean");
        }
        return signed;
    }

    private boolean isSigned(String str) {
        if ("+".equals(str) ) return false;
        if ("-".equals(str) ) return true;
        throw Util.failure("sign type dimension expects \"+\" or \"-\"");
    }
}
